The controversial chief executive of the Pennsylvania SPCA resigned suddenly Wednesday, but he may not be gone for good. Nelson closed the PSPCA's Stroudsburg shelter two weeks ago, blaming lack of local support and even threats from residents.

The controversial chief executive of the Pennsylvania SPCA resigned suddenly Wednesday, but he may not be gone for good.

Howard Nelson quit via an e-mail sent to board members late in the afternoon.

"It caught everybody by surprise," said Kevin Feeley, president of the public relations firm Bellevue Communications. Feeley has been retained by the PSPCA board of directors.

Nelson closed the PSPCA's Stroudsburg shelter two weeks ago, blaming lack of local support and even threats from residents. Local rescue groups took charge of the shelter's animals.

Nelson's departure does not necessarily mean the shelter will reopen.

"Nothing is going to change until we figure out our issues with Howard," Feeley said Thursday.

Nelson's resignation reads:

"Subject: Resignation

It is with deep sadness due to health reasons and an environment no longer conducive to my success or the success of the organization that I am forced to resign my position from the PSPCA.

Attempts to reach the executive committee with a transition period have been unsuccessful today, but I am available to help in any way.

I wish the PSPCA nothing but the best and please feel free to call me with any questions re: a transition.

Howard Nelson"

Feeley said, "As a result of that letter, members of the board were in discussions last night that included Howard. At the moment, we agree he is taking a leave of absence until we can figure out what happened, why it happened, and how best to move forward."

Feeley said officials don't know what led to the abrupt resignation message; he provided no further details.

Board member Beth Ann Smith White has agreed to serve as interim director pro bono "until we can resolve these issues and determine what comes next," Feeley said.

After the Stroudsburg shelter's closing, Nelson told the Pocono Record, "We have been physically threatened and dozens of local groups have reached out to us with disparaging and threatening words for many months and years."

He added, "Many others from the community have stated that 'they don't blame the PSPCA for leaving' given the current climate and we appreciate their understanding. We simply could not operate as a nonprofit in this environment."

The Pocono Record in December published an investigative report examining allegations of abuse of authority by the agency in its procedures for seizing animals from individuals, as well as alleged use of a controversial euthanasia method called the heart stick. The PSPCA denied the allegations.

Nelson came to the PSPCA from Washington, D.C., where he had been chief executive of the Washington Human Society since 2005.

His approach to the Monroe County shelter issue included a public meeting to address community outcry over animal abuse cases. The shelter was renovated, and Nelson announced plans to work towards a "no kill" policy. There was also high staff turnover at the facility.